281581555673664 has 147 divisors (see below), whose sum is σ = 837772643615827. Its totient is φ = 93859310369664.

The previous prime is 281581555673633. The next prime is 281581555673699. The reversal of 281581555673664 is 466376555185182.

The square root of 281581555673664 is 16780392.

It is a perfect power (a square), and thus also a powerful number.

281581555673664 is a `hidden beast` number, since 2 + 8 + 1 + 5 + 8 + 1 + 5 + 556 + 7 + 3 + 6 + 64 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 281581555673592 and 281581555673601.

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 3624525829 + ... + 3624603515.

Almost surely, 2^{281581555673664} is an apocalyptic number.

281581555673664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

281581555673664 is the 16780392-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 281581555673664

281581555673664 is an abundant number, since it is smaller than the sum of its proper divisors (556191087942163).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

281581555673664 is an frugal number, since it uses more digits than its factorization.

281581555673664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155404 (or 77692 counting only the distinct ones).

The product of its digits is 1451520000, while the sum is 72.

The spelling of 281581555673664 in words is "two hundred eighty-one trillion, five hundred eighty-one billion, five hundred fifty-five million, six hundred seventy-three thousand, six hundred sixty-four".